| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high-performance zoom lens system that has a remarkably reduced overall length of a lens and hence a reduced size, and has good balance between a wide view angle at a wide-angle limit and a high zooming ratio, and to provide an imaging device and a camera. <P>SOLUTION: The zoom lens system comprises a first lens group having positive power, a second lens group having negative power, a third lens group having positive power, and a fourth lens group having positive power, wherein in zooming, the first to the fourth lens groups are moved so that the air spaces between the respective lens groups should vary, to achieve magnification change, and wherein conditions: 53<(f<SB>T</SB>/f<SB>W</SB>)×f<SB>G1</SB>/t<SB>G1</SB><900,ω<SB>W</SB>≥30 and f<SB>T</SB>/f<SB>W</SB>≥4.5 (f<SB>G1</SB>is a composite focal length of the first lens group, t<SB>G1</SB>is a thickness of the first lens group,ω<SB>W</SB>is a half view angle at the wide-angle limit, and f<SB>T</SB>and f<SB>W</SB>are focal lengths of the entire system at the telephoto limit and at the wide-angle limit, respectively) are satisfied. The zoom lens system, the imaging device and the camera are provided. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
